Trends in Late-onset Sepsis in Very Low Birth Weight Preterm Infants in the Brazilian Network on Neonatal Research: A 10-year Cohort Study.

BACKGROUND

Late-onset sepsis (LOS) remains a leading cause of morbidity and mortality in preterm infants, with decreasing incidence in high-income countries but persistent challenges in low- and middle-income countries. This study aimed to evaluate the epidemiology, microbiological profile, and short-term outcomes of LOS in very low birth weight (VLBW) preterm infants in Brazil.

METHODS

A multicenter cohort study across 18 level 3 neonatal units of the Brazilian Network on Neonatal Research included 13,439 VLBW infants (400-1499 g birth weight, 22-36 weeks gestation) admitted between 2010 and 2020, excluding those with major malformations, congenital infections or death before 72 hours. Main outcomes included incidence of proven and clinical LOS, in-hospital mortality, and associated short-term morbidities.

RESULTS

The cohort had a mean gestational age of 29 ± 3 weeks and birth weight of 1079 ± 275 g. The incidence of proven LOS was 24.6%, and clinical LOS was 19.2%. Gram-positive bacteria predominated (64.1%, with 49.4% coagulase-negative staphylococci), followed by Gram-negative bacteria (27.2%) and fungi (8.8%). Over the decade, fungal infections decreased, while Gram-negative bacterial infections and proven LOS incidence increased. In-hospital mortality was 24.8%, showing no reduction. LOS was associated with an increased risk of death and severe morbidities.

CONCLUSIONS

This comprehensive 10-year cohort in Brazil reveals a concerning epidemiological shift, characterized by a significant increase in Gram-negative infections and a persistent, high LOS incidence and mortality among VLBW infants. These findings, particularly the lack of improvement in prognosis, underscore the urgent need for targeted and effective preventive and control interventions tailored for resource-limited settings.